An optical switch is a switch that selectively switches signals in optical fibers or integrated optical circuits (IOCs) from one circuit to another. An optical switch that performs the switching by routing light beams is called a “photonic” switch regardless of how the light itself is switched.
A photonic switch changes circuit connections purely at the optical layer, with no electrical conversion and processing being involved. Since there is no optical-to-electrical and electrical-to-optical conversion, a photonic switch is agnostic from the standpoint of circuit rate, data format and optical wavelength. The switching mechanisms of existing photonic switches have involved switching only a single optical path, and not switching multiple optical paths simultaneously.